Integrated circuits (ICs) form the basis for many electronic systems. Essentially, an integrated circuit (IC) includes a vast number of transistors and other circuit elements that are formed on a single semiconductor wafer or semiconductor chip and are interconnected to implement a desired function. Increasing complexity of these ICs leads to an increasing number of linked transistors and other circuit elements.
An individual integrated circuit or chip is usually formed from a larger structure known as a semiconductor wafer, which can be comprised of various materials such as silicon, gallium arsenide, indium phosphide, ceramic, copper, glass, glass-ceramic, lithium niobate, quartz, sapphire, silicon on insulator, and/or silicon on sapphire glass, among various other materials. Such wafers often have round peripheries and can have a plurality of integrated circuits arranged in rows and columns with the periphery of each integrated circuit being rectangular. The wafer can be sawn or “diced” into rectangularly shaped discrete integrated circuits along two mutually perpendicular sets of parallel lines, e.g., streets, lying between each of the rows and columns thereof. Hence, the separated or singulated integrated circuits are commonly referred to as dice.
An example, a wafer sawing operation can include attaching the wafer to a wafer saw carrier, mechanically, adhesively or otherwise, as known in the art, and mounting the wafer saw carrier on the table of the wafer saw. A blade of the wafer saw is passed through the surface of the wafer by moving either the blade relative to the wafer or the table of the saw and the wafer relative to a stationary blade, or a combination of both. In various cases, to dice the wafer, the blade cuts precisely along each street, returning back over (but not in contact with) the wafer while the wafer is laterally indexed to the next cutting location. Once all cuts associated with mutually parallel streets having one orientation are complete, the blade can be rotated 90 degrees relative to the wafer or the wafer can be rotated 90 degrees, and cuts can be made through streets in a direction perpendicular to the initial direction of cut.
Various dicing blades are available commercially. By way of example, a sintered diamond blade includes diamond particles which are fused into a soft metal such as brass or copper, or incorporated by means of a powdered metallurgical process; a plated diamond blade includes diamond particles which are held in a nickel bond produced by an electroplating process; and a resinoid diamond blade is one in which diamond particles are typically held in a resin bond to create a homogeneous matrix, among various other dicing blades.
The type of dicing blade used to dice a wafer can depend on various factors such as the type of wafer. For instance, the type of dicing blade used can depend on whether the wafer is comprised of silicon, glass, ceramic, sapphire, and/or a combination thereof. In some cases, the wafer can be a number of wafers bonded together forming a wafer stack. In such cases, each wafer of the stack can be comprised of a different material or a combination of different materials.
In dicing operations, the sharpness of the tool blade can affect the effectiveness of the cutting and/or the yield of a wafer dicing process. The blade sharpness can be affected by various factors including blade speed, torque, depth of cut, and feed rate, among others. Dull dicing blades can slow the wafer dicing process, which can cause problems such as reduced throughput as blades are replaced and/or sharpened. The high cost of these wafers, together with the value of the circuits fabricated on them, makes it difficult to accept anything less than high yield at the die-separation phase.